How Catholic is your Kennedy name?
Copyright © 2008 Iain Kennedy (updated 2nd November 2008)
Originally, all the Irish and Scottish Kennedys were Catholic. Almost all Irish Kennedys still are to this day (see for example the online 1911 census for Dublin which indicates religion). In Scotland proof of this ancient Catholicism can be seen in the entries of papal supplications, many of which were collected in the Vatican Archives by the late Annie Dunlop. See also the famous debate John Knox held against Quintin Kennedy at Maybole (check location). The Reformation did not touch the whole of Scotland and by chance, made the least impact in Lochaber which is the stronghold of the Highland Kennedys, with the result that many of them remain Catholic. Further north still on Lewis the Free Church, which split from the established Presbyterian Church in the nineteenth century, still dominates.
What is most interesting is to examine the religion of Irish Kennedys coming to Scotland. It is tempting to read too much into such information; sometimes we can determine where in Ireland they come from and sometimes not. The origin of the Catholic Kennedys in Northern Ireland, and those in Co. Donegal, are unclear, as is the arrival time of southern Dalcassian Kennedys into Ulster. Religious affiliations can change over time, particularly under political pressure. So what follows I hope is of interest but maybe not much more.
Percentage having a Roman Catholic marriage in Scotland (listed in descending order).
Patrick Kennedy 14/15
Michael Kennedy 8/10
Bernard Kennedy 7/10
Joseph Kennedy 3/12
Samuel Kennedy 0/18
Matthew Kennedy 0/10
These individuals have not yet been cross-checked in census and other records to determine exactly if they were Irish natives or of Irish descent. However none of these names were used in Scotland prior to the Irish migration period starting in the 1790s, apart from the occasional Samuel record.A recent academic study  has backed up these findings and pointed out another way of getting such figures, by utilising what is left of the Irish census returns where religion was a column to fill in on the enumerator's form. Best for this is Belfast where religion is a searchable field and there is a good mix of Catholic and Protestant Kennedys. The Dublin census is much more strongly RC although nonetheless, there are not insignificant numbers of Church of Ireland Kennedys there for comparison. You will also need to view the actual image of the return to confirm the religion.
 "Sectarianism, segregation and politics on Clydeside in the later nineteenth century" (John Foster, Muir Houston, Chris Madigan in "New Perspectives on the Irish in Scotland" ed. Martin Mitchell (2008)